Palmatine-Intercalated Montmorillonite Improves Intestinal Health and Attenuates Systemic Inflammation in ETEC-Challenged Piglets

Enterotoxigenic Escherichia coli (ETEC) infection severely impairs post-weaning piglet health, causing intestinal dysfunction, systemic inflammation, and significant economic losses in the swine industry. This study aims to evaluate a synthesized palmatine-intercalated montmorillonite composite (MP) for improving growth performance, immune response, and intestinal health in ETEC-challenged piglets. Following structural characterization, an in vivo trial was conducted using 30 crossbred piglets (Yorkshire × Landrace × Duroc; 15.12 ± 2.95 kg BW) challenged with ETEC K88 and supplemented with 0.02%, 0.5%, and 1.5% MP. Structural analysis confirmed successful intercalation of palmatine into montmorillonite, with enhanced antibacterial and anti-inflammatory properties. In vivo, dietary inclusion of the 1.5% MP significantly alleviated ETEC-induced growth depression, as evidenced by increased average daily gain and improved apparent total tract digestibility of crude protein. These effects were associated with improved jejunal morphology and upregulation of PEPT1, B0AT1, and SGLT1. Moreover, MP supplementation attenuated systemic inflammation and hepatic stress, as indicated by reduced serum AST, TNF-α, and IL-1β levels. Microbiota analysis showed that MP modulated ETEC-associated alterations in the cecal microbial community. In conclusion, the MP represents a promising nutritional approach to improve intestinal resilience, nutrient utilization, and growth performance of ETEC-challenged piglets.